Simple synthesis of carbon-11 labeled styryl dyes as new potential PET RNA-specific, living cell imaging probes

A new type of styryl dyes have been developed as RNA-specific, live cell imaging probes for fluorescent microscopy technology to study nuclear structure and function. This study was designed to develop carbon-11 labeled styryl dyes as new probes for biomedical imaging technique positron emission tomography (PET) imaging of RNA in living cells. Precursors (E)-2-(2-(1-(triisopropylsilyl)-1H-indol-3-yl)vinyl)quinoline (2), (E)-2-(2,4,6-trimethoxystyryl)quinoline (3) and (E)-4-(2-(6-methoxyquinolin-2-yl)vinyl)-N,N-diemthylaniline (4), and standards styryl dyes E36 (6), E144 (7) and F22 (9) were synthesized in multiple steps with moderate to high chemical yields. Precursor 2 was labeled by [11C]CH3OTf, trapped on a cation-exchange CM Sep-Pak cartridge following a quick deprotecting reaction by addition of (n-Bu)4NF in THF, and isolated by solid-phase extraction (SPE) purification to provide target tracer [11C]E36 ([11C]6) in 40–50% radiochemical yields, decay corrected to end of bombardment (EOB), based on [11C]CO2. The target tracers [11C]E144 ([11C]7) and [11C]F22 ([11C]9) were prepared by N-[11C]methylation of the precursors 3 and 4, respectively, using [11C]CH3OTf and isolated by SPE method in 50–70% radiochemical yields at EOB. The specific activity of the target tracers [11C]6, [11C]7 and [11C]9 was in a range of 74–111 GBq/μmol at the end of synthesis (EOS).

This paper reports the simple synthesis of new carbon-11 labeled styryl dyes as potential PET RNA-specific, living cell imaging probes.Figure optionsDownload as PowerPoint slide